Dry kiln



A. O. MILLER Feb. Z8, 1928.

DRY KILN Filed Jan. 3l. 1925 3 Sheets-Sheet l ...www N R O T N E V N ,f7/.LEN 0. IVI/LL ER ATTORNEY Feb. 28, 1928.

INVENTOR LLEN C? N/LER ATTORNEY Feb. 28, 1928.

A. O. MILLER DRY KILN Filed Jan. 31. 1925 3 Sheets-Sheet 3 C A TORNEY Patented Feb. 28, 1928.

UNITED STATES ALLEN 0. MILLEB, OF

DRY

Application led January Y This invention relates to improvements in dry kilns, and more particularly to kilns ofV that character especially designed for 'the drying of lumber and wherein mechanical means is provided for effecting a circulation of air through the kiln.

The principal object of this invention resides in the provision of a kiln of the above character having a longitudinally extending in air duct in which blower fans are located at intervals and operated to make possible a uick circulation of a large volume of air t rough the kiln and which is equipped with deflectors, or bailies of novel construction I Iand arrangement, some of wh-ich are ad]ustable to different positions to effect the proper and most satisfactory distribution and circulation of air for drying both edge and flat stacked lumber.

Another object resides in the arrangement of the fans on a single shaft which provides for a reversal of the current of drying air by a reversal in the direction of rotation of the fans.

Other objects reside in the various details of construction 4and combination of arts embodied in the invention as is hereinafter described.

In accomplishing these and other obgects of the invention, I have proved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein-- Figure 1 is longitudinal, sectional view of a dry kiln embodying the present invention.

Figure 2 is a horizontal, sectional view showlng the disposition of the air delivery fans and arrangement of baiiies and deiiectors along the air duct.

Figure 3 is a perspective view of a part of the air duct, particularly illustrating one of the adjustably, hinged deiiectors.

Figure 4 is a transverse, sectional view of the kiln showing the disposition of the hinged detlectors when drying fiat, stacked lumber.

' Figure 5 is a similar view showing their disposition for dr in ed e, stacked lumber.

Referring more 1n etai to the drawings- 1 and 2, respectively, designate the op posite side walls of a dry kiln constructed in accordance with the resent invention and 3 designates I-beams t at are extended transprovided the im- PATENT OFFICE.

SEATTLE, WASHINGTON.

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versely between the wnllsin s aced apart reil lation for the support of rai s 4 forming a track along which a truck on which the lumber is stacked for drying is movable into and from the kiln.

Extending longitudinally of the kiln, below the cross beams 3 and midway between the opposite side walls 1 and 2, is an air duct, designated at 6 having vertical, opposite side Walls 7 and 7 with outwardly inclined upper (portions 8-8 that extends upwardly beyon and along the outer sides of rails 4 and which overlap the top surfaces of heating radiators 9 supported by the beams?, along opposite sides of the kiln; the said radiators com rising a plurality of steam pipes arrange closely to ether and in par allel relation as is best slown in Figures 4 and 5.

Mounted rotatably in suitable supporting bearings 10 and extending longitudinally of the air duct is a shaft 11 on which, at regularly spaced intervals, blowery fans 12 are mounted. The shaft may be driven byany suitable means, such as the electric motor 13 that is located at one end of the kiln, as shown in Figure 1, and which has a belt and pulley driving connection with the end of the shaft.

The gist of this invention resides chiefly in the means for deiiecting and circulating the air through the stacked lumber in equally distributed and heated amounts and this is accomplished by the novel arrangement of defiectors and baffles in the air duct which will now be described. 9o

In the o posite side walls 7--7' of the air duct, just orward of each blower fan, o enings 15 are provided for the intakin o air and extending laterally and rearward y from the forward edge of these openings exce t the two at the extreme forward end of tie duct are wing deilectors 16. The air duct, between the walls 7-7 is closed oi by transverse partition walls 18 located just for wardly of each set of side openings 15 and the top of the duct, between the top edges of the walls 7'7 is covered b short wall sections 2() that extend rearwar ly from the upper edges of each partition wall 18 to points directly above the adjacent fan, at which points they join with the lower edges of vertical baille lates 2 1 that extend transversely between t e opposite aide walls 8-8 vide the deflector plates 32.

of the duct. 'lhe top of the duct between each ot the bullies 2l and partition wall 18 rearward thereof is uncovered to permit a free passage of air upwardly.

'lo ellect an upward deflection of air at a point midway between each of the fans and next rearward partition wall 18, I have placed' vertical iballles 24 acrossA the duct abofe the shaft 11. The air that is driven by the fans below these latter ballles is finally caused to be deflected upwardly by contact with the partition walls 18.

For the reason that there are two colnmon methods of stacking lumber for drying, namely, edge and flat stacking and lfor the reason that they require different methods of air-circulation to obtain satisfactory drying results, I have provided detieetors or battles that are adjustable and which may be moved to different positions to' obtainthe best results in accordance with the method of stacking used.

These deflectors, as shown best in Figures 4 and 5, comprise relatively long, liat plates 30 that are hingedly fixed along their lower edges, as shown at 3l, to the top edges of the walls 7 -7 in such manner that they may be folded outwardly to lie upon the upper -surfaces of the walls 8 8', as shown 1n Figure 5, or may be swung up to vertical position, as shown in'Figure 4. The end portions of the plates are turned inwardly at right angles to the body portion to pro- Hinged deflectors of this character are located opposite each other along the upper edges of the walls 7--7.

For drying flat stacked lumber, as shown f in Figure 4, the deflectors are swung upwardly on their hinged mountings so that the plates 30 extend substantially in vertical position or are inclined slightly toward each other and the end plates 32 of delectors at opposite sides of the duct are brought into overlapped relationv and are secured together by bolts extended through registering openings 3G provided therein. The deflectors-` when so disposed, cause the air to be directed into the triangular opening or recess provided in the center of the stack of lumber, and effect a better and quicker drying. The dellector plates 32 supplement the vertical dcflectors 2l and 2st for the purpose of directing the air currents upwardly.

When drying edge stacked lumber, as shown-in Figure 5, where it is desired that the air be directed over the entire lower surface of the stack, the deflector plates are disconnected and are swung outwardly, to rest upon the side walls 8-8. lVhen so disposed, they do not interfere with the outward spreading of the air and the deflector plates 32 again serve to deflect the air currents upwardly.

With the kiln so constructed and equipped,

it is readil apparent that a quick circulation of a Alin-ge volume of air is possible. The fans operate to drive the air from within the duct against the detlectors and balles upwardly through the'staeked lumber after which it travels downwardly along the side walls, between the heating pipes and again to the air duet'through the openings 15 provided therefor.

B arranging the blower fans on a single shaft extended the length of the kiln, it is possible to provide a brisk circulation of air, and the direction of this circulation ma be periodically reversed, when such is desired, by reversing the direction of the driving shaft. This would cause the air to be driven upwardly along the opposite sides of the stack and to be drawn downwardly through the stack and into the air duct. Such a reversal would prevent the lumber nearest to the fans from drying faster than that more distant.

Having thus described my invention, what I claim as new therein and desire to secure byLetters Patent, is:

1. In a dry kiln, the combination with an .air duct having top openings and means for delivering air from the same, of dellector plates supported at opposite sides of said openings and adjustable to control the direction of flow of the air.

2. In a dry kiln, the combination with an air duct havmg top openings through which air may be discharged, of deilector plates supported adjustably at opposite sides of the openings and movable from and toward each other` to control the direction and spread of the air stream as it is discharged.

3. In a dry kiln, the combination with an air duet having top openings for the discharge of air, of deflector plates hingedly fixed along their lower edges to the duct at opposite sides of the openings and adapted to be swung toward and from each other at their upper edges.

4. In a dry kiln, the combination with an air delivery duct having top openings for the delivery of air and provided with dcilectors for effecting an upward discharge of air through said openings, of paired defleclor plates hingedly fixed along their lower edges to the duct at opposite sides of the openings and adapted to be swung from or toward each other at their upper edges, and means for securing them so as to provide a relatively narrow discharge opening between their upper edges.

5. In a dry kiln, the combination with an air delivery duct having top openings for the delivery of air and provided with deflectors for effecting an upward discharge of air through said openings, of paired delector plates hingedlyl fixed along their lower edges to the duct at opposite sides of the openings and having laterally turned lll) opposite end portions forming baille plates and means for holding the deieetor plates at different positions of adjustment.

6. In a dry kiln of the class described, the combination with an air duct having top openings for the discharge of air and having dellectors therein for the upward deflection of air through said openings, of deflector plates hingedly fixed along their lower edges to the duct at opposite sides of the openings; said plates being adapted to swing toward and from each other at their upper edges and having laterall turned opposite end portions forming ba es provided with apertures, said bailles of plates at opposite sldes of the duct being adapted to overlap and to be secured together to provide a relatively narrow air discharge passage between the plates.

Signed at Seattle, King County, Washing- 20 

